This is part of a series of iTextSharp tutorials for VB 2010 Express. See this post for an overview and to answer any basic questions that you may have.
This post is a followup to the previous one, this time it scales the image based on the document’s size
Option Explicit On Option Strict On Imports System.IO Imports iTextSharp.text Imports iTextSharp.text.pdf Public Class Form1 Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load ''//The main folder that we are working in Dim WorkingFolder = Environment.GetFolderPath(Environment.SpecialFolder.Desktop) ''//The file that we are creating Dim WorkingFile = Path.Combine(WorkingFolder, "Output.pdf") Dim SampleImage = Path.Combine(WorkingFolder, "IMG_5605.JPG") ''//Create our file with an exclusive writer lock Using FS As New FileStream(WorkingFile, FileMode.Create, FileAccess.Write, FileShare.None) ''//Create our PDF document Using Doc As New Document(PageSize.LETTER) ''//Bind our PDF object to the physical file using a PdfWriter Using Writer = PdfWriter.GetInstance(Doc, FS) ''//Open our document for writing Doc.Open() ''//Insert a blank page Doc.NewPage() ''//Create a PDF image object from our physical image Dim ThisImage = iTextSharp.text.Image.GetInstance(SampleImage) ''//Use standard ratio resizing algorithms to calculate new image dimensions based on the documents dimensions. This will shrink or grow documents to fit ''//Will hold our new image dimensions ''//Documents sometimes have margins (and this sample does) so subtract them so that our image in centered in the page Dim NewW, NewH As Single NewW = Doc.PageSize.Width - (Doc.LeftMargin + Doc.RightMargin) NewH = Doc.PageSize.Height - (Doc.TopMargin + Doc.BottomMargin) ''//Scale the image ThisImage.ScaleToFit(NewW, NewH) ''//Add the image to the document Doc.Add(ThisImage) ''//Close our document Doc.Close() End Using End Using End Using Me.Close() End Sub End Class
Hi Chris,
I don’t get:
NewW = Doc.PageSize.Width
NewH = (Doc.PageSize.Height * NewW) / Doc.PageSize.Width
Doesn’t that equate to:
NewH = Doc.PageSize.Height
You’re right! The calculations should have used the image’s height/width. And actually, I updated the code above to remove those calculations completely and just use the
ScaleToFit
method which does all the work for us!Hey I have a question I have a loop going on here in this example below, yet when it gets to the first record in the loop of the list box, it bombs out. Any Idea why?
For i = 0 To lboxconv.Items.Count – 1
MsgBox(lboxconv.Items(i))
‘//GRAB THE EXTENSION WE ARE ADDING
Dim extension = Microsoft.VisualBasic.Right(i, 3)
‘//PROCESS THIS REQUEST
‘//PROCESS THIS AS PDF FILE
Dim doc As New Document()
Dim File_Type As String
File_Type = Replace(lboxconv.Items(i), “.png”, “.pdf”, vbTextCompare)
Dim writer As PdfWriter = PdfWriter.GetInstance(doc, New FileStream(File_Type, FileMode.Create))
doc.Open()
Dim imgpath As String = lboxconv.Items(i)
Dim png As iTextSharp.text.Image = iTextSharp.text.Image.GetInstance(imgpath)
png.ScaleToFit(“500”, “500”)
png.Alignment = Element.ALIGN_CENTER
doc.Add(png)
doc.Close()
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